How to deal with Orange Peel and only partially filled pores with Waterlox

[Alan Lightstone]

Despite significant effort filling the pores, it's obvious that the pores were only partially filled on the veneered top.

Here's been my process so far:

After sanding to 320 and dyeing with Transtint, two wiped on coats of dewaxed amber shellac. I squeegied on Pore-O-Pac, squeegied off excess, wiped with burlap, followed by 24hrs of drying. Then a light wet sanding with 320 grit sandpaper.

Then I brushed on one coat of Waterlox Sealer/Finish, wiped on one coat of S/F then wet sanded with 320 grit. Always waiting at least 24 hours between coats (yes, I've learned...)

I followed this stage with two more coats of S/F followed by a coat of Waterlox High Gloss Finish all wiped on. I was planning on waiting 24 hours, then wet sanding with 400 grit, then a few more coats, sanding with 600 grit, a final coat and waiting for it to cure before rubbing it out.

Unfortunately, the pores still aren't totally filled, plus the Waterlox High Gloss caused some orange peel (I think). Could it be that the Waterlox High Gloss finish was starting to go bad? It was a little thicker consistency than I'm used to with the S/F, so I thinned it about 10% with M/S. Is that how it normally is, or is this where the orange peel is coming from?

What's my best approach from here? I was thinking of wet sanding with 400 grit, applying another coat of Waterlox Gloss and seeing how it looked. But how many coats will it take to fill the partially filled pores? And will the orange peel just sand out?

Here's what it looks like now:

Orange-Peel-and-Pores-on-top.jpg

[Henry Ambrose]

Its done when its done.

I'd sand it back and put on another coat. It might take 2 or 3 more.
Keep the coats thin and give them plenty of time to cure.

[Alan Lightstone]

Its done when its done.

I'd sand it back and put on another coat. It might take 2 or 3 more.
Keep the coats thin and give them plenty of time to cure.

I came to that conclusion and did that.

Still wondering. Is the Waterlox High Gloss significantly more viscous than the Sealer/Finish? It seems ill suited for use as a wiping varnish. Doesn't level out nearly as well as the Sealer/Finish. Should I be thinning it more?

[Scott Holmes]

Waterlox Original mixed 50/50 with mineral spirts is a wiping varnish; striaght out of the can it's a brushing varnish.

The Waterlox S/F is basically just thinned Original with a low % flattener in it to make it a semi-gloss.

Why are you wet sanding better coats? Wet sanding is reserved for final sanding; not between coat sanding in my shop. Tends to get a wite slurry in the pores then there a pain to get out. Try a couple of brush on coats, then dry sand it back with 320 grit. Make sure you use a hard sanding block (cork or wood) to get it flat.

[Alan Lightstone]

I've had issues in the past with the sandpaper gumming up. That's why I've been wet sanding between coats. It's seemed much more forgiving in practice.

Do you need stearated sandpaper to dry sand between coats?

The 400 and 600 grit papers I have on hand are not stearated (They are Norton SandWet). The 320 grit sandpaper I have is (Norton 3X).

I had hoped that the pores would have been filled at this point with nowhere for the slurry to go except on top, (where it's easily wiped off) but clearly the pores have not been completely filled, despite significant effort on my part. I think they are getting close, but no cigar. That being said, I haven't noticed any of the slurry getting in the pores.

I can see in practice that Waterlox Orginal High Gloss is a brushing varnish. Without being thinned, it clearly doesn't seem thin enough to be used as a wiping varnish. Out of the can, Waterlox S/F wipes fine.

Hadn't used the original before, so lesson learned. My technique had been working fine with S/F. I had assumed (incorrectly) that their application would be similar.

Do you need stearated sandpaper to dry sand between coats?

The 320, 400, and 600 grit papers I have on hand are not stearated. I had hoped that the pores would have been filled at this point with nowhere for the slurry to go except on top, (where it's easily wiped off) but clearly the pores have not been completely filled, despite significant effort on my part. I think they are getting close, but no cigar. That being said, I haven't noticed any of the slurry getting in the pores.

[Howard Acheson]

>>>> I've had issues in the past with the sandpaper gumming up.

That's an indication that the finish has not dried and cured enough to be sanded. A finish is ready to be sanded when dry 320 paper produces a fine, white dust.

As far as sending between coats, the only places where sanding is normally used it to flatten and smooth after then initial sealer coat. Subsequent coats do not need sanding unless you are sanding out some miscue when applying the prior coat. As long as the prior coat has not been allowed to dry for 12 hours or more sanding is not required for adhesion. An already smooth and flat surface gains nothing by further sanding. The finest grit needed for between coat sanding is 400 grit. Sanding to a higher grit will not give you a smooth finish when another coat is applied. It is important that the sandpaper be attached to a flat felt or rubber surfaced sanding block and that the surface is sanded in the direction of the grain.

What I'm seeing in the picture is the result of too much finish applied to a non-flattened surface. Trying to flatten a surface by filling with finish can be problematic. It should only be attempted with a wood that has relatively shallow pores. Oaks would not be a good candidate for example.

The process is to first sand the surface as flat as you can. Use a long straightedge and lay it across and along the surface in a number of places. Make some scribble marks with a pencil wherever there is a high spot. Sand those spots and again use the straightedge. Continue until the whole surface is flat in every direction. Now thin some of your finish and apply a coat to the whole surface. Let it dry to the point where dry sanding produces powder. Sand the whole surface. Apply two fill strength coats and let it dry. Now comes the good part. Use a sharp cabinet card scraper and scrap the whole surface moving in the direction of the grain. Done correctly you should see non-glossy areas and lots of little glossy spots. These glossy spots are below the surface of the wood where the finish has not filled the pores. Apply another two to three coats, let it dry and again use your scraper. The glossy spots should be small or, if you are lucky, they will be good. Continue coating and scraping until all the glossy spots are gone. This indicates that the pores are completely filled. Check with your straightedge to be sure the surface is still flat. Once you get to this point, lightly sand with 320 paper and then carefully apply your final coat. If you plan to rub out further, apply at least two more coats so you have enough finish to sand some away without getting down the wood again. For rubbing out allow the finish to cure for 3-4 weeks before going at it.

Some finishers like to finish-fill with shellac or lacquer because it dries faster. They do dry faster but they have less solids. This means there is less solids to fill the pores. So while it dries faster, it will generally take more coats to fill the pores and flatten the surface.

Well, I'm off to France for a few weeks so any questions will have to wait until I return.

[Alan Lightstone]

Thanks for the response, Howie. Have a nice trip.

I've been waiting about 24 hours to sand. It's just to remove dust nibs and stray hairs that adhere to the surface. I've been using the technique by Michael Pekovich in Fine Woodworking (Mar/Apr 2011). Its basically 2 coats of Waterlox, sand with 400 (wet with varnish), then two more coats, followed by rubbing out. Looking at the pictures, he's using Waterlox Sealer/Finish, not High Gloss.

I have a real issue with dust nibs (despite air cleaners, etc..), so I've taken to sanding after every 2-3 coats to smooth. The technique worked great on the other side of the top. Up until today, I've done all my sanding with wet sanding, followed by wiping off the residue.

I just tried sanding dry with 320 grit stearated paper for the legs. They have been sitting about a week. No question I got fine dust powder, and the paper didn't clog. So, at least this time of year, in my part of the country, it takes curing more than 24 hours to be able to dry sand the Waterlox, and less than 7 days. More precisely, I don't know yet. And the weather/humidity keeps changing this week.

So, I guess the question I have, is can I just ignore all the dust nibs/hairs until just before the last coat, and just sand then?

[Henry Ambrose]

So, I guess the question I have, is can I just ignore all the dust nibs/hairs until just before the last coat, and just sand then?

Yes, but you still want to cut it back more often than the next to last coat, IMO. And you now know its ready to sand when you get fine dust from the sandpaper and not before. Wet sand with the Waterlox Sealer Finish thinned with a little mineral spirits. Sand it in with 320, don't wipe off, and let it dry a day or two then sand that back. I like this better from the start with bare wood but you might want to give it a try.

[Alan Lightstone]

I tried the wet sanding with Waterlox S/F on the opposite side, and thought it made the wood look a little muddy / obscured the grain some. That's the sanding method used by Pekovich in FWW, but it didn't work well for me. Perhaps I didn't wait long enough or sanded too much making too much wood dust mixed in with the Waterlox when it dried. He recommends that after the first two coats. I found on that side that just wet sanding with mineral spirits (or soapy water for that matter) did the trick.

I'm not real happy with the appearance of the High Gloss brushed on at this point. It didn't level out nearly as well as the S/F (although that is comparing brushed vs wiped on.) I will likely switch back to S/F then last sanding, and final coat.